The present invention relates to a key switch arrangement, and particularly to a key switch arrangement which can ensure an excellent operational performance.
Conventional key switch arrangements are disclosed in Taiwan Patent Application Nos. 83204123, 8121456, 84218262, 85202834, 85203.94, and U.S. Pat. Nos. 5,278,372; 5,278,374; 5,39,084; 5,399,822; 5,463,195; 5,278,371; and 5,504,283.
One kind of conventional key switch arrangement commonly comprises a key cap, a key switch subassembly slidably mounted to a bottom surface of the key cap for providing a switching effect, a key switch supporting plate having engaging portions for engaging with the key switch subassembly, a circuit membrane forming a switch electrode thereon, a rubber member mounted between the switch supporting plate and the circuit membrane for triggering the switch electrode of the membrane circuit, and a supporting plate attached under the circuit membrane for supporting the key switch arrangement. Such a conventional key switch arrangement has a significant height resulting a bulky key board.
In order to reduce the volume of a key board, another key switch arrangement has been introduced. Such a key switch arrangement commonly comprises a key cap, a key switch subassembly mounted to the key cap, a membrane circuit, a rubber member attached between the key switch subassembly and the circuit membrane for triggering the member circuit, and a supporting plate forming engaging portions thereon for engaging with the key switch subassembly and for supporting the entire key switch arrangement.
However, since the engaging portions of the supporting plate are usually integrally formed or stamped from the metal supporting plate, ragged edges are unavoidably formed on the engaging portions. The ragged edges adversely affect the operational continuity of the key switch assembly and may shorten the life-span of the key switch subassembly of the key board thereby increasing costs. In addition, since the supporting plate is made of resilient metal, the engaging portions are apt to deform during transport of components of the conventional key switch arrangement (including the supporting plate). When this happens, assembly of the key switch arrangement will become difficult.
Therefore, an improved key switch arrangement is required.